The present invention relates to a baler. More particularly this invention concerns a binding or tying arrangement for use in a so-called big-bale machine which produces large cylindrical bales tied circumferentially with twine or wire.
A type of baler is known which picks the cut crop, hay, alfalfa, or the like, up off the ground and advances it along a path into a bale-forming chamber. A plurality of tines is reciprocal along this path in order to advance the material along it, these tines also serving to precompress the material to be baled.
In such an apparatus once the requisite quantity of material is present in the baling chamber a plurality of needles are displaced across the path each pulling a respective baling twine or wire. These twines or wires are looped around the mass of material in the baling chamber so that, once they have been passed across the path, they can be tightened and tied off. Then the thus-tied bale can be ejected from the baling chamber, the needles can be withdrawn back across the feed path, and the next bale can be formed. It is therefore necessary in such devices to stop the material feed at least during the period when the needles cross the path. Even so a frequent occurrence is that the needles are deflected by the material in the path so that the tying mechanism cannot seize the end of the twine held by the needle and properly tie it off. Furthermore the needles are frequently bent to the point where the entire machine must be shut down and the needles either bent back to their proper positions or replaced before the baling operation can continue.
It has been suggested in a down pressing type of baler to protect the needles when they project into the pressing chamber by means of segment shields. The disadvantage of this arrangement is that the needles are not protected at all times by the shields. The shields are displaced in an opposite direction to the displacement direction of the needles so that the mass of material must be at least partially separated by the needles on one side and the shields on the other. This arrangement has some application to balers which produce a parallel-epipedal bales, but cannot be used with the above-described ball-type baler. See French Pat. No. 1,161,838, British Pat. No. 837,518 and 1,244,302 and German Auslegeschrift No. 1,782,382.